The invention generally relates to an anchoring and sealing system for cased hole wells.
A packer is a device that typically is used in a well to form an annular seal between an inner tubing string and a surrounding casing string. More specifically, the packer typically is part of the inner tubing string and contains a sealing element that is formed from one or more elastomer seal rings. The rings are sized to pass through the well when the packer is being run downhole into position, and when the packer is in the appropriate downhole position and is to be set, gages of the packer compress the seal rings to cause the rings to radially expand to form the annular seal. A number of different mechanisms may be used to develop the force to radially expand the seal rings, such as hydraulically, weight set or electrically actuated mechanisms.
Other types of packers may include sealing elements that are set without using a compressive force. For example, a packer may have an inflatable bladder that is radially expanded to form an annular seal using fluid that is communicated into the interior space of the bladder through a control line. As another example, a packer may have a swellable material that swells in the presence of a well fluid or other triggering agent to form an annular seal.